Our research on tiger sharks (Galeocerdo cuvier) to date has been in Australian tropical waters, but recently, we began investigating tiger sharks a little further afield. Together with South
African colleagues Ryan Daly, Clare Daly and Malcolm Smale I have been tagging tiger sharks off Ponta Do Oura in southern Mozambique. Ryan has been running a bull
shark project (called Zambezi shark in Africa) here for the last few years. This
field trip in January 2014 was the start of the tiger shark project which we are conducting in
collaboration with Mahmood Shivji from the Guy Harvey Institute.
Why Mozambique? Mozambique was a
good fit as Ryan already had the infrastructure in place and he sees tiger
sharks regularly while working on bull sharks.
But more importantly, there are a number of research groups around the
world tagging tiger sharks, so by eventually combining these data sets we are building
a picture of tiger shark movements and ecology at a global scale. Having never
had a tiger shark tracked in its waters, Mozambique is one of the holes we are
hoping to fill in forming a global understanding of tiger shark movements.
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| Done! the tag is attached |
The first shark we tagged was the
very first tiger shark ever tagged off the Mozambique coast. The shark was a
327 cm long male we named Matevula.
In the local dialect (Tsonga) this means "the first one"
or "a first”. He was fitted with both a satellite tag and acoustic transmitter.
The 2nd shark was also
a male of similar length (330 cm) which had an element of luck to the catch.
Well it was lucky for us! The shark
caught itself by getting its tail tangled in the fishing rope, not requiring
the hook and making our jobs easy.
Malcolm and I both had to leave
the project at the end of January, but we left 5 satellite and acoustic
transmitters with Ryan and Clare. They have managed to tag 2 more tiger sharks
since we left, another 330 cm male and a smaller female, 317 cm. They will look
to deploy the remaining tags over the next few months. Stay posted for updates
on the tagged sharks movements and new sharks tagged.
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| Matevula, swimming away with his new piece of jewellery |
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| Track of the 1st tiger shark tagged in Mozambique thus far. Note he is moving back and forth from Mozambique and South Africa – no passport required, but it does highlight the difficulties in conservation planning for mobile marine species i.e. conservation plans or lack of from multiple jurisdictions (countries) will affect the degree of protection a species is granted. And no, the shark is not moving out on to the land, the track over land is the error in the GPS location estimate, but he is moving close to the coast. |
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